The present invention relates generally to methods for application of polymeric film to a surface and related assemblies.
Painted surfaces are commonly used in many different types of applications. Painted surfaces may not only improve aesthetic properties, but they may also or alternatively improve functional properties of underlying surfaces and help protect the same. One such application is in the transportation industry, where exterior painted surfaces are typically exposed to a variety of environments, some of which can be very harsh on the surface. Examples of articles in the transportation industry having such painted surfaces include vehicles providing transportation over land, in the water, and in the air. Such vehicles include aircraft and motorized vehicles like automobiles and trucks. The paint on such surfaces can function to protect the underlying surface from damage due to that exposure. However, the paint itself must also be durable to withstand repeated exposure to such damaging environments.
Recently, paint in film form has been developed for application to such surfaces as an alternative to traditional paint, which traditional paint is typically liquid-based and applied to surfaces in its liquid form. Paint in film form is based on at least one polymeric film and is also referred to herein as a “polymeric film” or “polymeric paint film.” An example of such polymeric paint film is described in U.S. Patent Publication No. US-2010-0059167-A1, entitled “Paint Replacement Films, Composites Therefrom, and Related Methods.”
Yet, as with application of other polymeric films to surfaces, particularly those surfaces having complex topographies, adequate adhesion at an interface and effective removal of entrapped air between the polymeric film and the underlying surface has proven to be a challenge. For example, in many cases, as adhesive adhering the polymeric film attaches to an underlying surface, which adherence does not necessarily progress along a uniform front, particularly as topography of the underlying surface increases in complexity (i.e., such that it contains significant convex and concave portions), air often becomes entrapped at the interface between the polymeric film and the underlying surface. Due to the adhesive's presence at the advancing front, beyond which is entrapped air, air becomes increasingly difficult to completely remove as adherence of the polymeric film progresses. As such, mechanisms for facilitating air bleed from such interfaces have been explored.
Many conventional air bleed mechanisms rely on use of structured adhesive layers to remove entrapped air. For example, see U.S. Patent Publication No. 2011/0111157 and U.S. Pat. No. 7,332,205. Another polymeric film structure known to facilitate air bleed between the structure and an underlying surface after application includes a microstructured surface, such as that described in U.S. Pat. No. 5,897,930. While effective in many applications, such microstructures have been found to obscure optical clarity in certain applications. For example, structure from the adhesive layer is often still visible (including to the naked human eye) after application of the polymeric film to an underlying surface. Visibility is even more pronounced as thickness of the polymeric film decreases and/or transparency of the polymeric film increases. As is readily understood, this presents a less than ideal solution to the problem of removal of entrapped air. In addition, types of polymeric films able to be effectively applied to an article's surface are limited by the constraints associated with presence of such a microstructured surface.
Thus, alternative methods for application of polymeric films to a surface and related assemblies are desired.